/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.metadata.schemaregion.rocksdb.mnode;

import org.apache.iotdb.commons.exception.MetadataException;
import org.apache.iotdb.db.metadata.mnode.IMNode;
import org.apache.iotdb.db.metadata.mnode.MNodeType;
import org.apache.iotdb.db.metadata.mnode.container.IMNodeContainer;
import org.apache.iotdb.db.metadata.schemaregion.rocksdb.RSchemaConstants;
import org.apache.iotdb.db.metadata.schemaregion.rocksdb.RSchemaReadWriteHandler;
import org.apache.iotdb.db.metadata.schemaregion.rocksdb.RSchemaUtils;
import org.rocksdb.RocksDBException;

public class RInternalMNode extends RMNode {

    private volatile boolean useTemplate = false;

    /**
     * Constructor of MNode.
     *
     * @param fullPath
     */
    public RInternalMNode(String fullPath, RSchemaReadWriteHandler readWriteHandler) {
        super(fullPath, readWriteHandler);
    }

    @Override
    void updateChildNode(String childName, int childNameMaxLevel) throws MetadataException {
        String innerName =
                RSchemaUtils.convertPartialPathToInner(
                        childName, childNameMaxLevel, RMNodeType.INTERNAL.getValue());
        try {
            readWriteHandler.updateNode(innerName.getBytes(), new byte[]{});
        } catch (RocksDBException e) {
            throw new MetadataException(e);
        }
    }

    /**
     * check whether the MNode has a child with the name
     */
    @Override
    public boolean hasChild(String name) {
        String childPathName = fullPath.concat(RSchemaConstants.PATH_SEPARATOR).concat(name);
        IMNode node = getNodeBySpecifiedPath(childPathName);
        return node != null;
    }

    /**
     * get the child with the name
     */
    @Override
    public IMNode getChild(String name) {
        String childPathName = fullPath.concat(RSchemaConstants.PATH_SEPARATOR).concat(name);
        return getNodeBySpecifiedPath(childPathName);
    }

    /**
     * add a child to current mnode
     *
     * @param name  child's name
     * @param child child's node
     * @return
     */
    @Override
    public IMNode addChild(String name, IMNode child) {
        child.setParent(this);
        String childName = fullPath.concat(RSchemaConstants.PATH_SEPARATOR).concat(name);
        int childNameMaxLevel = RSchemaUtils.getLevelByPartialPath(childName);
        try {
            if (child instanceof RMNode) {
                ((RMNode) child).updateChildNode(childName, childNameMaxLevel);
            } else {
                logger.error("Rocksdb-based is currently used, but the node type received is not RMNode!");
            }
        } catch (MetadataException e) {
            logger.error(e.getMessage());
        }
        return child;
    }

    /**
     * Add a child to the current mnode.
     *
     * <p>This method will not take the child's name as one of the inputs and will also make this
     * Mnode be child node's parent. All is to reduce the probability of mistaken by users and be more
     * convenient for users to use. And the return of this method is used to conveniently construct a
     * chain of time series for users.
     *
     * @param child child's node
     * @return return the MNode already added
     */
    @Override
    public IMNode addChild(IMNode child) {
        addChild(child.getName(), child);
        return child;
    }

    /**
     * delete a child
     */
    @Override
    public IMNode deleteChild(String name) {
        String childPathName = fullPath.concat(RSchemaConstants.PATH_SEPARATOR).concat(name);
        int nodeNameMaxLevel = RSchemaUtils.getLevelByPartialPath(childPathName);
        for (RMNodeType type : RMNodeType.values()) {
            byte[] childInnerName =
                    RSchemaUtils.convertPartialPathToInner(childPathName, nodeNameMaxLevel, type.getValue())
                            .getBytes();
            try {
                if (readWriteHandler.keyExist(childInnerName)) {
                    readWriteHandler.deleteByKey(childInnerName);
                    return null;
                }
            } catch (RocksDBException e) {
                logger.error(e.getMessage());
            }
        }
        // The return value from this method is used to estimate memory size
        // When based on Rocksdb, mNodes are not held in memory for long periods
        // Therefore, the return value here is meaningless
        return null;
    }

    /**
     * replace a child of this mnode
     *
     * @param oldChildName measurement name
     * @param newChildNode new child node
     */
    @Override
    public void replaceChild(String oldChildName, IMNode newChildNode) {
        if (!oldChildName.equals(newChildNode.getName())) {
            throw new RuntimeException("New child's name must be the same as old child's name!");
        }
        deleteChild(oldChildName);
        addChild(newChildNode);
    }

    @Override
    public IMNodeContainer getChildren() {
        throw new UnsupportedOperationException();
    }

    @Override
    public MNodeType getMNodeType(Boolean isConfig) {
        return isConfig ? MNodeType.SG_INTERNAL : MNodeType.INTERNAL;
    }

    @Override
    public boolean isUseTemplate() {
        return useTemplate;
    }

    @Override
    public void setUseTemplate(boolean useTemplate) {
        this.useTemplate = useTemplate;
    }
}
